The cost of building and maintaining a double set of steel fences along 700 miles of the U.S.-Mexico border could be five to 25 times greater than congressional leaders forecast last year, or as much as $49 billion over the expected 25-year life span of the fence, according to the nonpartisan Congressional Research Service.

A little-noticed study the research service released in December notes that even the $49 billion does not include the expense of acquiring private land along hundreds of miles of border or the cost of labor if the job is done by private contractors -- both of which could drive the price billions of dollars higher.

The Congressional Research Service also questioned the effectiveness of a fence in preventing people from crossing the border illegally, especially if it does not span the entire 1,952-mile border. Secure fencing of some kind already exists along 106 miles of border, mostly in short stretches around cities.

The findings did not deter Congressional backers of the border fence, including Rep. Duncan Hunter, R-San Diego, the fence's principal proponent.

"Mr. Hunter firmly supports expanding the San Diego border fence across the U.S.-Mexico border," said spokesman Joe Kasper. "This doesn't have to be and should not be as costly an endeavor as some are suggesting."

Congress has so far provided the Department of Homeland Security with $1.5 billion for upgrading infrastructure and technology at the border this fiscal year, which ends Sept. 30. No money has been allocated specifically for the 700 miles of fence.

A spokesman for Sen. Dianne Feinstein, D-Calif., was circumspect as to how the money should be spent, given the report's findings.

"Sen. Feinstein has been supportive of the idea of a fence and thinks it has been effective in California," said Feinstein spokesman Scott Gerber. "At the same time, we have to be realistic about the costs of both construction and maintenance. Priorities need to be made, estimates need to be made based on the real world, and as additional information comes forward, we'll take another look at it."

The fence would be built under the auspices of the Department of Homeland Security, which oversees Customs and Border Protection. Boeing Co., under a September contract with Homeland Security, already has begun constructing a "virtual fence" along all 6,000 miles of the U.S. border, north and south, that is expected to run to $2.5 billion.

A state-of-the-art fence constructed on almost 10 miles of border in western San Diego County has reduced the number of Border Patrol arrests of illegal entrants there, the research service reported.

But "the flow of illegal immigration has adapted to this enforcement posture and has shifted to the more remote areas of the Arizona desert," the research service said. The number of arrests along the entire border in 2004 was 1.2 million, the same as in 1992, before the San Diego fence was built and other enforcement was increased.

"The main difference is that, while San Diego accounted for the majority of apprehensions in 1992, in 2004 (the) Tucson and Yuma sectors accounted for the majority of apprehensions," the study noted.

When the House of Representatives first approved a border security bill last winter, Hunter estimated it would cost $2.2 billion. The Congressional Budget Office echoed that figure in May with an estimate of $3 million per mile -- $2.1 billion for 700 miles.

But the Congressional Research Service noted that the 14-mile San Diego fence is expected to cost $9 million per mile once it is finished. The research service also used a larger figure -- 850 miles -- for the length of the fence.

Recent fences along the border have been constructed by the U.S. Army Corps of Engineers for Customs and Border Protection. The Corps has obtained the land, drafted the environmental protection plan, designed the project and overseen construction. Labor has been provided by National Guard and military units on loan from the Department of Defense.

The Dec. 12, 2006, nonpartisan congressional report said the corps predicted that the combined cost of building and maintaining the fence over a 25-year life cycle would range from $16.4 million to $70 million per mile, depending on how heavily and how often the fence is damaged by would-be border jumpers. At $70 million per mile, a 700-mile fence would cost $49 billion.

Though much land on the border in California and Arizona already belongs to the federal government, most of the Texas and New Mexico borderlands are privately held. And 70 miles of Arizona border lie along the Tohono O'odham Indian Reservation, whose leaders have vowed to fight the fence, a stance that could lead the government into a protracted legal battle.

Douglas Massey, a professor of sociology at Princeton University who studies the border and illegal immigration, said the government should spend its money differently.

"It's a waste of money," he said. "If you want to increase security, better to use some of that money for ports and transportation systems. If you want to lower the rate of Mexican immigration to the U.S., I would spend it on development assistance for Mexico."

A guest worker program would reduce the illegal traffic at the border, he also said, and free up the Border Patrol to focus on keeping out drug smugglers and potential terrorists.

Rep. Tom Tancredo, R-Colo., who has spoken adamantly in favor of restricting both legal and illegal immigration, remains a supporter of the fence for security reasons as well.

"It's simple: What did 9/11 cost us versus what would it cost to maintain a fence to help prevent that?" said Carlos Espinosa, a Tancredo spokesman. "If we could prevent another terrorist attack, then absolutely it's worth it."

Walls do work, as long as they're defended. The Berlin Wall worked just fine, until they decided to tear it down. Oh sure, a few people made it through anyway, and a few people got killed, but the vast majority stayed on their side of the wall and lived with the consequences. And that's the real problem, isn't it? If walls didn't work, it'd just be a waste of money, and the government wastes money all the time. Most people don't give a damn. But if it works - even in the statistical sense of reducing the flow - then the consequences aren't just a budget number.

I honestly do not think a wall the size that one would need to be could do what they want it to do. 700 miles? We're not talking a mere city & we're not talking about back in the days when people were on horse back or merely on foot & we do not live in a world where it is acceptable to shoot people on sight~~ the public has a cow every time there's a police shooting, you have to justify use of deadly force on a guy who has a criminal history full of violence/armed robbery/assault~~ Can you imagine if you shot Jose for climbing a wall? In the United States? And the Mexican government blatantly encourages its citizens to come over here for health care & jobs. And those guys doing the transporting of people, the coyotes, have the same type of equipment we do; radios, cell phones, GPS,wireless laptops, & a corrupt Mexican government to look the other way. It's big business. And for a good long bit of those 700 miles there's nothing out there... think of the cost of moving workers into those primitive, isolated areas & housing them while you pay them & pay to have the goods brought in to build the wall~~ in Presidio, Texas, right now, half the homes don't even have a phone & that's on the TEXAS side. I've been in a home there where the floor was still dirt & the old woman had a hole dug with rocks around it & that's where she cooked her meals, that's how poor it is on THIS side down there. And there already IS a wall between El Paso & Juarez. Hasn't stopped the flow the least bit. They just got smarter. They got scanners & put the police/border patrol freqs in & listen & they cross where the cops/agents aren't. And they dug tunnels. I live here in SW Texas, on the Border, & I'm in LE. People are already pissed that they now have to have a passport to come back from Mexico, which, to us, isn't really like another country. How are you going to man a wall 700 miles long? Start up the draft? Nobody wants that. Maybe electrify the fence? Then you're going to have to build power stations & keep THEM manned & maintained.

So, in my opinion, a wall in this day & age & in this particular situation will not work because of economic/social/political reasons. Walls have only ever worked in the short term to begin with; they are not a solution, they are a stop gap measure you take & historically they seem to be a rather desperate last ditch effort.

Believe me, I'm all for reducing the flow, but I think the real long term answer lies more in making Mexico economically healthier & in penalizing the corporations hiring illegals & in the US stopping the providing of health care & food stamps & Lone Star cards & WIC~~ which is a whole 'nother can of worms. Because that's pretty much impossible too & would anger & set off yet more of the general public.

And there already IS a wall between El Paso & Juarez. Hasn't stopped the flow the least bit.

Actually, it has, and the example of El Paso and San Diego have worked do well that it's motivating walls in other cities. It doesn't stop the flow entirely, but it greatly limits the flow at that point, which is great for the citizens of those places. The flow is moved out to the middle of the desert, where fewer American landowners are impacted.

There's a really great article I linked a while back about the economic pressure of border enforcement, including walls, which cause people to come through a much more roundabout (and expensive, and dangerous) direction, and even the migrants admit is deterring quite a few.

This year, with weeks of daily attempts, it took them a month to get past border patrols. Once the group got over the fence, it was a three-day walk across the desert into Phoenix. Previous trips -- through now-impassable Escondido, Calif., took about a day.

But other migrants aren't even that fortunate. Many were stuck at the border and forced to return to their homes, contributing to this year's worker shortages. Although Tepec plans to come back because of financial needs, he predicts others won't. The new risks are too great.

All I can tell you is I am 3 hours from El Paso. I have numerous friends in LE there, including in DHS & Border Patrol. Nobody there thinks the wall thing is very effective; they, the ones on the street, are NOT seeing a marked decrease in illegals. They ARE seeing a marked increase in improved fake IDs & DLs & passports & green cards so it's harder to figure out if the person actually is illegal~~ & we've fired & arrested several Driver's License Techs in the McAllen/Laredo area for providing DLs & IDs to illegals.

The only people claiming it's working, from where I sit, in LE, are the ones apparently talking to the newspapers & Bush & for whom it means job security & possible wage increases & long term employment~~ the El Paso wall is a joke down here to the people actually living in El Paso/Juarez. They found a tunnel you can drive a vehicle in. I don't know about Arizona, New Mexico, California. I'm not there, I don't know anyone in LE who could tell me honestly what it's actually like on the streets there. All I know about is Texas. Laredo is a war zone right now. Google that if you haven't read about the drug cartel kidnappings & murders/executions going on there already. The wall idea's great in theory but I haven't seen enough hard, physical evidence, as a citizen of Texas, as an officer in Texas, as someone who was born & grew up on the border, to think it's more than a big flashy AP headline grabbing political move.

That largely depends on what you mean by "effective". All the things you mention are actually signs of effectiveness if you're looking at it from the standpoint of economic pressure. For example, if they're using better IDs, that means they've been diverted from hopping the wall to coming through the gates with forged documentation. And any kind of pressure would result in better IDs. If we'd started checking IDs and deporting people with crappy ones, that would result in improvement too. They only used bad IDs because there was no pressure. We weren't even bothering to deport on that basis, so what does it matter if they were easy to detect?

Anyway, the upshot of all this is that it's becoming more difficult and more expensive to be here illegally. Sure, you can buy better IDs, but it means more cost, and more risk. And as cost goes up, demand goes down. Which is exactly what we're seeing.

Given enough money and ruthlessness, a wall can work, in the sense of keeping people out (or in). From what I understand, the Berlin wall was pretty good at keeping East Germans from fleeing. However, I strongly doubt that the U.S. would be willing to spend enough money or behave ruthlessly enough to make U.S. border fence as effective as the Berlin Wall. And I definitely don't think that it's good for the U.S. on either an ethical or an economic basis.

It doesn't have to be anywhere near as effective as the Berlin Wall to work.

Illegals are coming here to work for a pittance. Raise the price of making it across the border, and some will decide it's better to stay at home. And incremental changes have incremental effects. Each increase in price decreases the number of crossers. It'll only approach 0, never hit it, but by that point you've got a much higher ratio of enforcers to crossers, the only crossers are highly motivated, so you automatically have some interesting information about the people who try anyway.

(Incidentally, cost pressure doesn't have to come from a fence. "Operation Wetback" worked very well simply by enforcing immigration law at the job site. Not only did only did immigration slow, it reversed. In that way, it may be better than a fence. But a fence + enforcement is better still.)

Mexicans who earn dollars trade something of value (labor) for little bits of papers (dollars). If the dollars they send to Mexico are then eventually spent in the U.S. then they will be used to buy other U.S. goods and services (no loss to the U.S.) If they never return, then the U.S. is richer by the value of the labor exchanged for those (now lost) bits of paper. Either way, remittances are no loss to the U.S.

That would be true if there was some trade, but there isn't. Shipping money - and the value it represents - overseas with no return flow is identical to dumping it in the ocean. There's some small benefit to be gained in reducing the money supply, but I don't see you burning your cash to increase the value of the dollar, so I suspect it's not optimal from an opportunity cost perspective.

And then there's the fact that this money doesn't just disappear, but is instrumental in propping up a corrupt government on our immediate border. We would be better off if we did dump it in the ocean.

Not that I support the notion of a wall inbetween the U.S.A. and Mexico. But if they're going to do one anyway...

Imagine giving them a less expensive and (maybe) more politically feasible option, as follows:

Offer, as a private company, to build the "barrier" at no cost to the government, other than the granting of the land (after they clear ownership of it all) with complete autonomy (reverting to a self-governing U.S. territory or such).

This buffer state free zone will allow both U.S. and Mexican citizens to visit, live & work, within the territory, without visa requirements.

Build a wall on either side, a high-speed train down the middle and a sea port on either side. Although you'd want then, all 2000 miles of the border, not just some middle 700 miles worth.